"if it is tested in a controlled setting with repeated results" is the statement among the choices given in the question that best describes that can possibly make this scientific claim valid. The correct option among all the options that are given in the question is the first option or option "A". I hope the answer has helped you.<span>
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<u>Answer:</u> The percent composition by mass of hydrogen in given compound is 6.33 %
<u>Explanation:</u>
We are given:
A chemical compound having chemical formula of 
It is made up by the combination of 1 nitrogen atom, 5 hydrogen atoms, 1 carbon atom and 3 oxygen atoms
To calculate the percentage composition by mass of hydrogen in the compound, we use the equation:

Mass of compound = ![[(1\times 14)+(5\times 1)+(1\times 12)+(3\times 16)]=79g/mol](https://tex.z-dn.net/?f=%5B%281%5Ctimes%2014%29%2B%285%5Ctimes%201%29%2B%281%5Ctimes%2012%29%2B%283%5Ctimes%2016%29%5D%3D79g%2Fmol)
Mass of hydrogen = 
Putting values in above equation, we get:

Hence, the percent composition by mass of hydrogen in given compound is 6.33 %
Answer:
0.04 M
Explanation:
Given data:
Mass of Na₂SO₄= 14.2 g
Volume of solution = 2.50 L
Molarity of solution = ?
Solution:
Number of moles of Na₂SO₄:
Number of moles = mass/ molar mass
Number of moles = 14.2 g/ 142.04 g/mol
Number of moles = 0.1 mol
Molarity :
Molarity = number of moles of solute / volume of solution in L
Molarity = 0.1 mol / 2.50 L
Molarity = 0.04 M
Answer: 1 mole of H2O= about 1/3 of a cup (18 mL). It is helpful ... 6.02 x 1023 H2O molecules. = 6.02 x 1023 NaCl formula unit. 1 mole C. 1 mole H2O. 1 mole
Explanation: